Merge "Minor improvements on LocalPreferences."

import android.annotation.Nullable;

import android.content.Context;

import android.content.SharedPreferences;

import android.content.SharedPreferences.Editor;

import android.os.UserHandle;

import android.preference.PreferenceManager;

    @Retention(RetentionPolicy.SOURCE)

    public @interface PermissionStatus {}

    /**

     * Clears all preferences associated with a given package.

     *

     * <p>Typically called when a package is removed or when user asked to clear its data.

     */

    static void clearPackagePreferences(Context context, String packageName) {

        clearScopedAccessPreferences(context, packageName);

    }

    private static void clearScopedAccessPreferences(Context context, String packageName) {

        final String keySubstring = "|" + packageName + "|";

        final SharedPreferences prefs = getPrefs(context);

        Editor editor = null;

        for (final String key : prefs.getAll().keySet()) {

            if (key.contains(keySubstring)) {

                prefs.edit().remove(key).apply();

                if (editor == null) {

                    editor = prefs.edit();

                }

                editor.remove(key);

            }

        }

        if (editor != null) {

            editor.apply();

        }

    }